Notching relay



1932- J. A. CLARKE, JR 1,871,777

NOTCHING RELAY Filed Jan. 30, 1930 a 6 c c 20 1 JII/ZZ 2/ l I 7 23 24 E 6 I J 27 I J 4/ INVENTOR ATTORNEY Patented Aug. 16, 1932 UNHTED STATES JOHN A. CLARKE, J R., 01? PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA NOTCHING RELAY Application filed January 30, 1930. Serial No. 424,546.

My invention relates, generally, to control systems for motor vehicles.

The object of the invention, generally stated is to provide a control system for mo tor-driven vehicles that shall be simple and efficient in operation and that may be readily and economically manufactured and installed.

A more specific object of the invention is to provide for effecting a step-loy-stepopera- 1 tion of the sequence drum of a control system for a motor-driven vehicleto control the operation of the propelling motors.

It is also an object of the invention to provide for advancing the sequence drum of a control system for vehicles independently of the current flowing in the motor, thereby to increase the motor torque.

Other objects of the invention will, in part,

c be obvious and will, in part, appear hereinafter.

The invention, accordingly, is disclosed in the embodiment thereof shown in the accompanying drawing and comprises the structural features, the combination of elements 2 an d an arrangement of parts that will be ex emplified in the structure hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawing which is a diagram showing the circuit connections of a motor-control system arranged in accordance with this invention.

Referring now to the drawing, 10 designates. generally, the propelling motor of a vehicle, such as a street car. A resistance 11 is connected in series with the motor to control the supply of current which may be fed to the motor from any suitable source, such as a trolley conductor 12.

As shown, the accelerating switches 13 and 14 are provided for shunting the sections of the resistor 11. In this instance, only two accelerating switches are illustrated, but it will be readily understood that as many as desired may be utilized.

In this particular control system, a sequence drum 15 is provided for controlling the op eration of the accelerating switches. As shown an air engine 16 is provided for operating the sequence drum 15.

In order to provide for the control of the system, a controller drum 17 of any well known type may be employed to connect the control apparatus to the trolley conductor 12. In order to explain the novel features of the invention, the operation of the control system will now be described. Assuming that it is desired to start the vehicle, the controller drum will be actuated to its initial position a, a circuit will be there-by established to extend from the trolley conductor 12, through trolley wheel 18, conductor 19, contact fingers 20 and 21bridged by the contact segment 22 of the controller drum 17, conductor 23, contact fingers 25 and 26bridged by the contact segment 28 and conductor 29, to the contact segment 30 of the sequence drum 15. 3

Therefore, the contact segment 30'of the sequence drum is energized.

A circuit extends fromthe energized conductor 29, through conductor 31, the actuating coil of the air valve 32 of the air engine 16, to ground at 33. In such manner, the valve 32 of the on valve of the air engine 16 is actuated to admit air to bias the piston and rack mechanism 34: downwardly, as viewed in the drawing. The other valve 35 of the air engine 16, or, as it is generally called, the off valve, stands in the opposite position to the on valve 32 when it is deenergized, that is, when the off valve is deenergized, air is admitted to the cylinder to bias the pistons and the rack 34 upwardly. Therefore, when the actuating coil on the on valve 32 stands energized, and the actuating coil of the off valve stands deenergized, the air engine is in a static condition.

Assuming that it is desired to rotate the sequence drum, the controller drum 1'7 is advanced to position b, and an energizing circuit for the actuating valve 35 of the air engine is established. This actuating circuit extends from the energized contact segment 28 of the drum 17, through contact finger 27, conductor 36, contact segment 37 of the sequence drum 15, conductor 38, the sequence relay 39, conductor 40, the current-limit relay 41, conductors 42 and 43 and the actuating coil of the air valve 35, to round at 44. Upon the energization of the actuating coil of the air valve 35, the Supply of compressed air to the lower cylinder is interrupted, and air is exhausted from the cylinder. As a result, the pistons and the rack will move-downwardly and, through the pinion 45, will rotate the sequence drum.

With a view to preventing the possible overtravel of the sequence drum, the relays 3'9 and 41 are disposed to interrupt the energizing circuit of the actuating coil of the air valve 35. In this particular system the sequence relay 39 will function before the current-limit relay.

41 is actuated.

The sequence relay 39 of this particular embodiment of the invention is provided with two coils 46 and 47. The coils are disposed to act cumulatively, when energized. The coil 46 is capable oflifting the relay armature independently of the coil 47 and may, therefore, be called alifting coil. The coil 47 is not capable of lifting the armature of the relay, but, when the relay has been actuated, it is capable of retaining the armature in its uppermost position. For convenience in description, it will hereinafter be called the holding coil.

As explained hereinbefore, upon the energization of the air valve 35, the sequence drum is advanced to engage, in a predetermined order, the contact fingers 48 to 54, inclusive.

When the contact fingers 4'8 and 49 are bridgedby one of the laterally extendingprojections of the contact segment 30, an actuating circuit for the sequence relay 39 is-esta-blished. This circuit may be traced from the energized contact segment 30, through contact finger '48, conductor and the lifting coil 46, to ground at 56; therefore, the sequence relay 39 is actuated to interrupt the energizing circuit of the actuating coil of the air valve 35.

In order to prevent the stopping'of the sequence drum before the laterally extending projection of the contactsegment 30' has been moved across the contact fingers 48 and 49, provision is made for establishing an energizing circuit for the actuating coil of the air valve 35 simultaneously with the establishment of the actuating circuit for the sequence relay 39. The circuit established for energizing the actuating coil of the air valve 35 may be traced from the energized contact seg ment 30, through contact finger 49., conductors 42 and 43 and the actuating coil of the valve, to ground at 44. Therefore, the air engine 16 continues to operate and to advance the sequence drum after the actuation of the sequence relay 39. .3

It will be noted that,as the sequencedrum advances, an actuating circuit for the .accelerating switch 13 is established. The circuit extends from the energized contact segment 30, through contact finger 51, conductor 57 and the actuating coil of accelerating switch 13, to ground. In this manner, the switch 13 is closed, and a section of the resistor 11 is shunted.

Upon shunting the resistor section, there will be a sudden. increase in the motor current which normally results in the actuation of the current-limit relay 41. As will be observed, the currentlimit'relay is disposed to interrupt the energizing circuit of the actuating coil of the air valve 35 which was establis'hed upon the actuation of the controller drum 1'? to its second position. Therefore, if the currentlimit relay 41 functions before, or simultaneously with, the disengagement of the contact linger 48 from the laterally extending projection provided on the contact segment 30, the energizing circuit of the actuating coil of the air magnet 35 will be interrupted, thereby stopping the air engine, and the sequence drum with the contact lin ers 48 and 49 positioned between two of the laterally extending projections of the contact segment 30.

It will be readily understood from the foregoing description that the operation of the current-limit relay 41 depends upon the operation of the sequence-drum accelerating switch 13 and the building up of a large motor current. As a result, the current-li1nit relay 41 does not always function quickly enough to'stop the air engine and sequence drum in the desired position.

In this particular system, the sequence relay 39 is actuated to interrupt the first established energizing circuit for the actuating coil of the air valve 35 at the moment the contact lingers 48 and 49 are engaged by the laterally extending projection provided on the contact segment 30. Therefore, if the limit switch does not function before, or at the same time, as the contact fingers 48 and 49 are disengaged from the contact segment 30, the sequence relay which has been .actu

ated will prevent further energiz-ation. of the actuating coil of the air valve 35 for a sufficient period of time to permit the operation of the current-limit relay 41. The relay will drop to its closed position, under the influence of gravity, when the contact finger 48 is disengaged from the contact segment 39. However, the time period occupied in the closing of the sequence relay 39 is sullicient to permit the operation of the current-limit relay 41.

When the motor l'O'is accelerated to a predetermined speed, the counter-electromotive force developed will decrease the motor current to a value which will permit the currentlimit relay 41 to close and reestablish the energizing circuit for the actuating coil of the valve 35 which was initially established through the actuation of the drum 17 to position b. The air engine will be operated again to advance the sequence drum another step, and the accelerating switch 14 will be closed in the manner described for the operation of the accelerating switch 13.

Assuming now that the vehicle which the motor is operating is standing on a steep grade, then, under such circumstances, it may be that the current which flows in the motor circuit, when the switch 13 is actuated to shunt a section of the resistor, will not develop sufficient torque to start the vehicle, and it may be desired to close the accelerating switch 14 to momentarily develop a greater torque in the motor. It will be readily understood that, as soon as the accelerating switch 13 is closed, the current-limit relay 41 will be actuated before the sequence drum can be advanced to operate the accelerating switch 14. If desired the switch 14 may be actuated independently of the current-limit relay 41 during starting operations.

In order to provide for closing the accelerating switch 14 independently of the currentlimit relay 41, a notching relay 58 is provided to cooperate with the sequence relay 39 to establish an energizing circuit for the actuating coil of the air valve when the control drum 17 is advanced to position 0.

Assuming now that it is desired to close the accelerating switch 14 independently of ourrent-limit relay 41, then cont-roller drum 17 is advanced to position a to establish a circuit which extends from the energized contact segment 28, through contact finger 24, conductor 59 and the actuating coil of the notching relay 58, to ground at 60. In this manner, the notching relay is closed and an energizing circuit for the actuating coil of the air valve 35 is established which extends from the energized contact 37 of the sequence drum through contact finger 54, conductor 38, the sequence relay 39, conductor 40, notching relay 58, conductor 61 and the actuating coil of the air valve 35, to ground at 44. Therefore, the air engine 16 is set in operation to advance the sequence drum 15.

It will be noted that the holding coil 47 of the sequence relay 39 is connected between the conductor 59 and ground at 56. Therefore, the holding coil 47 and the notch ing relay 58 are energized simultaneously, through actuation of the drum 17, to position c. In the process of advancing the sequence drum one step to effect the closure of the accelerating switch 14, the contact fingers 48 and 49 are engaged by the contact segment 30, and the energizing circuit for the lifting coil 46 of the sequence relay 39 is established. Therefore, the armature of the sequence relay 39 is actuated to its uppermost position to interrupt the energizing circuit of the actuating coil of the air valve 35. In this manner, the air engine and sequence drum are stopped to prevent the closing of more than one accelerating switch.

The advancement of the sequence drum through one step interrupts the energizing circuit established for the lifting coil 46 of the sequence relay 39. However, it will be M readily understood that the energizing circuit for the holding coil 47 is maintained as long as the controller drum 17 stands in position c. Iherefore, the energizing circuit for the actuating coil of the air engine cannot be reestablished to eifect the operation of the air engine and sequence drum without first actuating the controller drum 17.

Assuming that more than two accelerating switches are provided, and it is desired to further increase the motor current to obtain a greater starting torque, then the controller drum 17 is rotated in either direction to in terrupt the energizing circuit of the holding coil 47 of the sequence relay 39. After the sequence relay 39 is closed, the controller drum 17 may be actuated into position 0 again to reestablish the energizing circuit for the notching relay 58 and, in the manner described hereinbefore, to effect the operation of the air engine 16 and sequence drum 15 to close a motor-accelerating switch (not shown).

The motor circuits established upon the closure of the different accelerating switches have not been traced, since these circuits will be obvious to those skilled in the art.

The above description sets forth, in detail, a control system in which the accelerating switches are closed in a predetermined sequence to accelerate the propelling motor step-by-step, or any desired number of accelcrating switches may be closed to supply an overload current to the motor to develop a desired starting torque.

Since many changes may be made in the above construction, and different embodiments of the invention may be made without departing from the spirit thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as'my invention:

1. In a control system for vehicle motors,

in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of the accelerating switches, means for actuating the sequence drum step-by-step, a limit switch for controlling the step-by-step operation of the sequence drum, means for effecting a step-by-step operation of the sequence drum independently of the limit switch, thereby to actuate the accelerating switches and supply a predetermined current to the motor, and means cooperating with the sequence drum to stop the said drum after it has moved one notch.

52. In a control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of the accelerating switches, means for actuating the sequence drum step-by-step to effect the operation of the accelerating switches, a current-limit relay responsive to the motor currents, a sequence relay cooperative with the current-limit relay to stop the sequence drum in predetermined positions and to prevent overtravel of the sequence drum and means for effecting a step by-step operation of the sequence drum independently of the limit relay.

3. In a control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of the accelerating switches, means for actuating the sequence drum step-by-stcp t0 efilect the operation of the accelerating switches, a current-limit relay responsive to the motor currents, a sequence relay cooperative with the current-limit relay to stop the sequence drum in predetermined positions, and a notching relay cooperative with the means for actuating the sequence drum for effecting the operation of the sequence drum to closethe accelerating switches independently of the current-limit switch.

4. In a control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for cont-rolling the operation of the accelerating switches, means for actuating the sequence drum step-by-step to effect the operation of the accelerating switches a current-limit relay responsive to the motor currents, a sequence relay coopera tive with the current-limit relay to stop the sequence drum in predetermined positions, and a notching relay cooperative with the means for actuating the sequence drum to operate the sequence drum independently of the current-limit relay, said sequence relay being disposed to cooperate with the notching relay to give the sequence drum a step-bystep movement.

5. In a control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of the accelerating switches, an air engine for actuating the sequence drum, a current-limit relay, a sequence relay cooperative with the current-limit relay to give the sequence drum a step-by-step movement, a control'drum disposed for operation to initiate the operation of the air engine, and a notching relay disposed to cooperate with the sequence relay to effect a step-by-step operation of the sequence drum upon the operation of said control drum.

6. In a. control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of said switches, an air engine for operating the sequence drum, a control drum for initiating the operation of the air engine, a current-limit relay, a sequence relay cooperative with the current-limit relay to effect a 'step-by-step operation of the sequence drum, a notching relay cooperative with the sequence relay to effect a step-by-step operation of the sequence drum when the control drum is actuated to cause the energization and deenergizati on of said notching relay.

7. In a control system for vehicle motors, in combination, a plurality of accelerating switches, a sequence drum for controlling the operation of the accelerating switches, means for actuating the sequence drum, a controller drum for initiating the operation of the se quence drum, a notching relay disposed for operation upon the actuation or" the controller drum to effect the operation of the sequence drum-actuating means, and a sequence relay disposed to limit the movement of the sequence drum to a single step for each energization of the notching relay, thereby to provide a manual control for operating the accelerating switches to permit the application of any predetermined voltage to the vehicle motors.

In testimony whereof, I have hereunto subscribed my name this 20th day of January,

JOHN A. CLARKE, J11. 

